You may also like

2-digit Square

A 2-Digit number is squared. When this 2-digit number is reversed and squared, the difference between the squares is also a square. What is the 2-digit number?

Consecutive Squares

The squares of any 8 consecutive numbers can be arranged into two sets of four numbers with the same sum. True of false?

Plus Minus

Can you explain the surprising results Jo found when she calculated the difference between square numbers?

Order the Products

Age 14 to 16 Short Challenge Level:

Without calculating the five products below, put them in order of size, from smallest to largest. 

210$\times$190 198$\times$202 200$\times$200

195$\times$205 186$\times$214

This problem is taken from the World Mathematics Championships
You can find more short problems, arranged by curriculum topic, in our short problems collection.